FIG. 2 shows a conventional food packaging system of the type generally described in Japanese Patent Laid-Open Publication No. 255128/1987. As shown in FIG. 2, this packaging system 51 forms packaging containers 53 folded in a plate-like shape into bottomed containers having a bottom 53a. After the containers have been filled with liquid food, a seal is provided on the respective containers. The system includes a transfer conveyor that intermittently and continuously transfers the packaging containers 53 and a forming device 55 that forms folded packaging containers 53 into bottomed containers to feed them onto the transfer conveyor. A filling device 57 fills food product from above into the packaging containers 53 moving on the transfer conveyor, and a sealing device 59 seals the top of the packaging containers 53 filled with the food product. With this packaging system 51, packaging containers 53 can be continuously filled with liquid food and packaged in the sealed state.
To maintain the quality of the packaged food for a long period of time, it is known to sterilize the inside of the packaging container 53 before it is filled with food. The sterilizing agent can be hydrogen peroxide. In these systems, the hydrogen peroxide is used only for sterilization. Thus, after the hydrogen peroxide is deposited inside the packaging container 53, the hydrogen peroxide must be thoroughly removed before commencing the filling of the food product so that residual hydrogen peroxide in the container is kept below a specified value.
However, with the above packaging system 51 that forms packaging containers 53 into bottomed containers and continuously fills the container interior with food product, to increase or maximize productivity, the food product must be filled into the container in as short a time period as possible after depositing the hydrogen peroxide. Thus, a sterilizing agent removing method that can rapidly and reliably remove the deposited hydrogen peroxide is needed.